zipinfo - Unix, Linux Command

NAME

SYNOPSIS

zipinfo [-12smlvhMtTz] file[.zip]
[file(s) ...] [-xxfile(s) ...]

unzip-Z [-12smlvhMtTz] file[.zip]
[file(s) ...] [-xxfile(s) ...]

DESCRIPTION

zipinfo lists technical information about files in a ZIP archive, most
commonly found on MS-DOS systems. Such information includes file access
permissions, encryption status, type of compression, version and operating
system or file system of compressing program, and the like. The default
behavior (with no options) is
to list single-line entries for each file in the archive, with header and
trailer lines providing summary information for the entire archive. The
format is a cross between Unix ls -l and unzip -v
output. See
DETAILED DESCRIPTION below. Note that zipinfo is the same program as unzip (under
Unix, a link to it); on some systems, however, zipinfo support may
have been omitted when unzip was compiled.

ARGUMENTS

Tag

Description

file[.zip]

Path of the ZIP archive(s). If the file specification is a wildcard,
each matching file is processed in an order determined by the operating
system (or file system). Only the filename can be a wildcard; the path
itself cannot. Wildcard expressions are similar to Unix egrep(1)
(regular) expressions and may contain:

Tag

Description

*

matches a sequence of 0 or more characters

?

matches exactly 1 character

[...]

matches any single character found inside the brackets; ranges are specified
by a beginning character, a hyphen, and an ending character. If an exclamation
point or a caret (! or ^) follows the left bracket, then the range of
characters within the brackets is complemented (that is, anything except
the characters inside the brackets is considered a match). To specify a
verbatim left bracket, the three-character sequence [[] has to be used.

(Be sure to quote any character that might otherwise be interpreted or
modified by the operating system, particularly under Unix and VMS.) If no
matches are found, the specification is assumed to be a literal filename;
and if that also fails, the suffix .zip is appended. Note that
self-extracting ZIP files are supported, as with any other ZIP archive;
just specify the .exe suffix (if any) explicitly.

[file(s)]

An optional list of archive members to be processed, separated by spaces.
(VMS versions compiled with VMSCLI defined must delimit files with commas
instead.)
Regular expressions (wildcards) may be used to match multiple members; see
above. Again, be sure to quote expressions that would otherwise be expanded
or modified by the operating system.

[-xxfile(s)]

An optional list of archive members to be excluded from processing.

OPTIONS

Tag

Description

-1

list filenames only, one per line. This option excludes all others; headers,
trailers and zipfile comments are never printed. It is intended for use in
Unix shell scripts.

-2

list filenames only, one per line, but allow headers (-h), trailers
(-t) and zipfile comments (-z), as well. This option may be
useful in cases where the stored filenames are particularly long.

-s

list zipfile info in short Unix ls -l format. This is the default
behavior; see below.

-m

list zipfile info in medium Unix ls -l format. Identical to the
-s output, except that the compression factor, expressed as a
percentage, is also listed.

-l

list zipfile info in long Unix ls -l format. As with -m
except that the compressed size (in bytes) is printed instead of the
compression ratio.

-v

list zipfile information in verbose, multi-page format.

-h

list header line. The archive name, actual size (in bytes) and total number
of files is printed.

-M

pipe all output through an internal pager similar to the Unix more(1)
command. At the end of a screenful of output, zipinfo pauses with a
--More-- prompt; the next screenful may be viewed by pressing the
Enter (Return) key or the space bar. zipinfo can be terminated by
pressing the q key and, on some systems, the Enter/Return key. Unlike
Unix more(1), there is no forward-searching or editing capability.
Also, zipinfo doesnt notice if long lines wrap at the edge of the
screen, effectively resulting in the printing of two or more lines and the
likelihood that some text will scroll off the top of the screen before being
viewed. On some systems the number of available lines on the screen is not
detected, in which case zipinfo assumes the height is 24 lines.

-t

list totals for files listed or for all files. The number of files listed,
their uncompressed and compressed total sizes , and their overall compression
factor is printed; or, if only the totals line is being printed, the values
for the entire archive are given. The compressed total size does not include
the 12 additional header bytes of each encrypted entry. Note that the total
compressed (data) size will never match the actual zipfile size, since the
latter includes all of the internal zipfile headers in addition to the
compressed data.

-T

print the file dates and times in a sortable decimal format (yymmdd.hhmmss).
The default date format is a more standard, human-readable version with
abbreviated month names (see examples below).

-z

include the archive comment (if any) in the listing.

DETAILED DESCRIPTION

zipinfo has a number of modes, and its behavior can be rather difficult to fathom
if one isnt familiar with Unix ls(1) (or even if one is). The default
behavior is to list files in the following format:

The last three fields are the modification date and time of
the file, and its name. The case of the filename is respected; thus
files that come from MS-DOS PKZIP are always capitalized. If the file
was zipped with a stored directory name, that is also displayed as part
of the filename.

The second and third fields indicate that the file was zipped under
Unix with version 1.9 of zip. Since it comes from Unix, the file
permissions at the beginning of the line are printed in Unix format.
The uncompressed file-size (2802 in this example) is the fourth field.

The fifth field consists of two characters, either of which may take
on several values. The first character may be either t or b, indicating
that zip believes the file to be text or binary, respectively;
but if the file is encrypted, zipinfo
notes this fact by capitalizing the character (T or B). The second
character may also take on four values, depending on whether there is
an extended local header and/or an extra field associated with the
file (fully explained in PKWares APPNOTE.TXT, but basically analogous to
pragmas in ANSI C--i.e., they provide a standard way to include non-standard
information in the archive). If neither exists, the character
will be a hyphen (-); if there is an extended local header but no extra
field, l; if the reverse, x; and if both exist, X. Thus the
file in this example is (probably) a text file, is not encrypted, and
has neither an extra field nor an extended local header associated with it.
The example below, on the other hand, is an encrypted binary file with an
extra field:

.ti +2m
RWD,R,R 0.9 vms 168 Bx shrk 9-Aug-91 19:15 perms.0644
.ti -2m

Extra fields are used for various purposes (see discussion of the -v
option below) including the storage of VMS file attributes, which is
presumably the case here. Note that the file attributes are listed in
VMS format. Some other possibilities for the host operating system (which
is actually a misnomer--host file system is more correct) include
OS/2 or NT with High Performance File System (HPFS), MS-DOS, OS/2 or NT
with File Allocation Table (FAT) file system, and Macintosh. These are
denoted as follows:

File attributes in the first two cases are indicated in a Unix-like format,
where the seven subfields indicate whether the file: (1) is a directory,
(2) is readable (always true), (3) is writable, (4) is executable (guessed
on the basis of the extension--.exe, .com, .bat, .cmd
and .btm files are assumed to be so), (5) has its archive bit set,
(6) is hidden, and (7) is a system file. Interpretation of Macintosh file
attributes is unreliable because some Macintosh archivers dont store any
attributes in the archive.

Finally, the sixth field indicates
the compression method and possible sub-method used. There are six methods
known at present: storing (no compression), reducing, shrinking, imploding,
tokenizing (never publicly released), and deflating. In addition, there are
four levels of reducing (1 through 4); four types of imploding (4K or 8K
sliding dictionary, and 2 or 3 Shannon-Fano trees); and four levels of
deflating (superfast, fast, normal, maximum compression). zipinfo
represents these methods and their sub-methods as follows: stor;
re:1, re:2, etc.; shrk; i4:2, i8:3, etc.;
tokn; and defS, defF, defN, and defX.

The medium and long listings are almost identical to the short format except
that they add information on the files compression. The medium format lists
the files compression factor as a percentage indicating the amount of space
that has been removed:

Note that because of limitations in the MS-DOS format used to store file
times, the seconds field is always rounded to the nearest even second.
For Unix files this is expected to change in the next major releases of
zip(1L) and unzip.

In addition to individual file information, a default zipfile listing
also includes header and trailer lines:

The header line gives the name of the archive, its total size, and the
total number of files; the trailer gives the number of files listed,
their total uncompressed size, and their total compressed size (not
including any of zips internal overhead). If, however, one or
more file(s) are provided, the header and trailer lines are
not listed. This behavior is also similar to that of Unixs ls -l;
it may be overridden by specifying the -h and -t options
explicitly.
In such a case the listing format must also be specified explicitly,
since -h or -t (or both) in the absence of other options implies
that ONLY the header or trailer line (or both) is listed. See the
EXAMPLES section below for a semi-intelligible translation of this
nonsense.

The verbose listing is mostly self-explanatory. It also lists file
comments and the zipfile comment, if any, and the type and number of bytes
in any stored extra fields. Currently known types of extra fields include
PKWAREs authentication (AV) info; OS/2 extended attributes; VMS
filesystem info, both PKWARE and Info-ZIP versions; Macintosh resource
forks; Acorn/Archimedes SparkFS info; and so on. (Note
that in the case of OS/2 extended attributes--perhaps the most common
use of zipfile extra fields--the size of the stored EAs as reported by
zipinfo may not match the number given by OS/2s dir command:
OS/2 always reports the number of bytes required in 16-bit format, whereas
zipinfo always reports the 32-bit storage.)

Again, the compressed size figures of the individual entries include the
12 extra header bytes for encrypted entries. In contrast, the archive total
compressed size and the average compression ratio shown in the summary
bottom line are calculated without the extra 12 header bytes of
encrypted entries.

ENVIRONMENT OPTIONS

Modifying zipinfos default behavior via options placed in
an environment variable can be a bit complicated to explain, due to
zipinfos attempts to handle various defaults in an intuitive,
yet Unix-like, manner. (Try not to laugh.) Nevertheless, there is some
underlying logic. In brief,
there are three priority levels of options: the default options;
environment options, which can override or add to the defaults; and
explicit options given by the user, which can override or add to
either of the above.

The default listing format, as noted above, corresponds roughly
to the "zipinfo -hst" command (except when individual zipfile members
are specified).
A user who prefers the long-listing format (-l) can make use of the
zipinfos environment variable to change this default:

Tag

Description

Unix Bourne shell:

ZIPINFO=-l; export ZIPINFO

Unix C shell:

setenv ZIPINFO -l

OS/2 or MS-DOS:

set ZIPINFO=-l

VMS (quotes for lowercase):

define ZIPINFO_OPTS "-l"

If, in addition, the user dislikes the trailer line, zipinfos
concept of negative options may be used to override the default
inclusion of the line. This is accomplished by preceding the undesired
option with one or more minuses: e.g., -l-t or --tl,
in this example. The first hyphen is the regular switch character, but the
one before the t is a minus sign. The dual use of hyphens may seem a
little awkward, but its reasonably intuitive nonetheless: simply ignore
the first hyphen and go from there. It is also consistent with the behavior
of the Unix command nice(1).

As suggested above, the default variable names are ZIPINFO_OPTS for VMS
(where the symbol used to install zipinfo as a foreign command
would otherwise be confused with the environment variable), and ZIPINFO
for all other operating systems. For compatibility with zip(1L),
ZIPINFOOPT is also accepted (dont ask). If both ZIPINFO and ZIPINFOOPT
are defined, however, ZIPINFO takes precedence. unzips diagnostic
option (-v with no zipfile name) can be used to check the values
of all four possible unzip and zipinfo environment variables.

EXAMPLES

To get a basic, short-format listing of the complete contents of a ZIP
archive storage.zip, with both header and totals lines, use only
the archive name as an argument to zipinfo:

zipinfo storage

To produce a basic, long-format listing (not verbose), including header and
totals lines, use -l:

zipinfo -l storage

To list the complete contents of the archive without header and totals
lines, either negate the -h and -t options or else specify the
contents explicitly:

zipinfo --h-t storage
zipinfo storage \*

(where the backslash is required only if the shell would otherwise expand
the * wildcard, as in Unix when globbing is turned on--double quotes around
the asterisk would have worked as well). To turn off the totals line by
default, use the environment variable (C shell is assumed here):

setenv ZIPINFO --t
zipinfo storage

To get the full, short-format listing of the first example again, given
that the environment variable is set as in the previous example, it is
necessary to specify the -s option explicitly, since the -t
option by itself implies that ONLY the footer line is to be printed:

The -s option, like -m and -l, includes headers and
footers by default, unless otherwise specified. Since the environment
variable specified no footers and that has a higher precedence than the
default behavior of -s, an explicit -t option was necessary
to produce the full listing. Nothing was indicated about the header,
however, so the -s option was sufficient. Note that both the
-h and -t options, when used by themselves or with
each other, override any default listing of member files; only the header
and/or footer are printed. This behavior is useful when zipinfo is
used with a wildcard zipfile specification; the contents of all zipfiles
are then summarized with a single command.

To list information on a single file within the archive, in medium format,
specify the filename explicitly:

zipinfo -m storage unshrink.c

The specification of any member file, as in this example, will override
the default header and totals lines; only the single line of information
about the requested file will be printed. This is intuitively what one
would expect when requesting information about a single file. For multiple
files, it is often useful to know the total compressed and uncompressed
size; in such cases -t may be specified explicitly:

zipinfo -mt storage "*.[ch]" Mak\*

To get maximal information about the ZIP archive, use the verbose
option. It is usually wise to pipe the output into a filter such as
Unix more(1) if the operating system allows it:

zipinfo -v storage | more

Finally, to see the most recently modified files in the archive, use
the -T option in conjunction with an external sorting utility
such as Unix sort(1) (and sed(1) as well, in this example):

zipinfo -T storage | sort -nr -k 7 | sed 15q

The -nr option to sort(1) tells it to sort numerically
in reverse order rather than in textual order, and the -k 7 option
tells it to sort on the seventh field. This
assumes the default short-listing format; if -m or -l is
used, the proper sort(1) option would be -k 8.
Older versions of sort(1) do not support the -k option,
but you can use the traditional + option instead, e.g.,
+6 instead of -k 7. The sed(1)
command filters out all but the first 15 lines of the listing. Future
releases of zipinfo may incorporate date/time and filename sorting
as built-in options.

TIPS

The author finds it convenient to define an alias ii for zipinfo
on systems that allow aliases (or, on other systems, copy/rename the
executable, create a link or create a command file with the name ii).
The ii usage parallels the common ll alias for long listings in
Unix, and the similarity between the outputs of the two commands was
intentional.

BUGS

As with unzip, zipinfos -M (more) option is overly
simplistic in its handling of screen output; as noted above, it fails to detect
the wrapping of long lines and may thereby cause lines at the top of the screen
to be scrolled off before being read. zipinfo should detect and treat
each occurrence of line-wrap as one additional line printed. This requires
knowledge of the screens width as well as its height. In addition,
zipinfo should detect the true screen geometry on all systems.

zipinfos listing-format behavior is unnecessarily complex and should
be simplified. (This is not to say that it will be.)

SEE ALSO

zip(1L), zipcloak(1L), zipnote(1L), zipsplit(1L)

URL

AUTHOR

Greg Cave Newt Roelofs. ZipInfo contains pattern-matching code
by Mark Adler and fixes/improvements by many others. Please refer to the
CONTRIBS file in the UnZip source distribution for a more complete list.